After little crash I'm hearing strange knife-like sounds from my disk brakes, but the wheel and brakes doesn't look damaged. What should I do?
- Anybody can ask a question
- Anybody can answer
- The best answers are voted up and rise to the top
An unaligned caliper (the unit that sits over the disc) is far more likely than a bent rotor. It's more exposed and susceptible to being knocked.
You should first try to realign your disc brake caliper as this will quickly show if it is a rotor straightness or caliper alignment issue. This is a simple job and will only require the correct sized hex wrench.
If it's just a very short "zing" once every revolution, there's nothing to worry about -- it's pretty normal at least for downhill-oriented bikes to have their discs slightly out of true and bending them back will probably do more damage than good.
Otherwise, you should either take the bike to your LBS to get the disc trued or get a truing tool and do it yourself.